At the heart of the hunt is a specially designed £5 commemorative coin, inspired by Sir Isaac Newton, one of the most celebrated masters of the Mint, whose surface is embedded with numbers, letters and symbols concealing layers of riddles and puzzles. The coin will not enter general circulation.

The competition is structured across five levels. Level one is available free of charge via a dedicated microsite on the Royal Mint’s website, and serves as an introduction to the challenge; however, it does not form part of the competition itself. To progress through levels two to five, the stages that count towards winning, entrants must purchase either the brilliant uncirculated edition of the coin at £22.50, or the silver proof version at £149.50, as the coin and its packaging are required to solve subsequent puzzles. A gold edition is also available at £5,195.

Entrants must complete all four competitive levels by 11.59pm on 30th March. The competition is open to UK residents aged 18 and over, with one entry permitted per customer account. One winner will be selected at random on or shortly after 31st March and notified by email. Whilst anyone may attempt level one for enjoyment, only UK-based players are eligible to win the grand prize.

Broadcaster and mathematician Bobby Seagull, who was named “player one” and gifted the first-ever minted edition of the coin, described it as “a cryptographic masterpiece” and “a physical key that turns symbols and numbers into a brilliant puzzle”.

Nicola Mitchell, chief commercial officer at the Royal Mint, said the coin is “not just a beautiful collector’s item” but “an interactive device with more than meets the eye”, designed for those who love “mystery, challenge and the thrill of the chase”.